RRC Connection Establishment, Re-Establishment, and Resumption in a Wireless Communication System

ABSTRACT

A wireless device ( 14 ) transmits, to a radio network node ( 12 ), a radio resource control (RRC) connection request ( 18 ) that requests the establishment, re-establishment, or resumption of an RRC connection ( 16 ). The RRC connection request ( 18 ) indicates a type of core network to which the wireless device ( 14 )selects to connect. The wireless device ( 14 ) in some embodiments receives a response to the RRC connection request ( 18 ), based on the type of core network to which the wireless device ( 14 ) selects to connect. For example, the wireless device ( 14 ) may receive the response using a protocol stack determined based on the type of core network to which the wireless device ( 14 ) selects to connect.

TECHNICAL FIELD

The present application relates generally to a wireless communicationsystem and relates more particularly to a radio resource control (RRC)connection in such a system.

BACKGROUND

In order to re-establish or resume an RRC connection in a Long TermEvolution (LTE) radio access network (RAN), a wireless device transmitsa request for such re-establishment or resumption to the RAN and the RANresponds with a message that includes RRC connection parameters. Afterthe RRC connection has been re-established or resumed, the wirelessdevice may communicate with the RAN using one of different possibleprotocol stacks, depending on the type of core network to which thewireless device selects to connect, e.g., an Evolved Packet Core (EPC)or a 5G Core (5GC). These protocol stacks differ, for example, in thatthey use different versions of the packet data convergence protocol(PDCP).

SUMMARY

Some embodiments herein enable determination of the type of core networkto which the wireless device selects to connect, even during a procedurefor establishing, re-establishing, or resuming an radio resource control(RRC) connection. One or more embodiments for instance indicate the typeof core network to which the wireless device selects to connect in anRRC connection request that the wireless device transmits. These andother embodiments may thereby advantageously exploit a core network typespecific protocol stack even for communicating during at least a portionof the RRC connection procedure, rather than delaying use of such aprotocol stack until after the RRC connection procedure. This in turnmeans that, when the wireless device connects to a 5G Core for example,communication during at least a portion of the RRC connection proceduremay already benefit from any security protocol enhancements in the 5Gprotocol stack, instead of those 5G enhancements being postponed untilafter the RRC connection procedure.

More particularly, embodiments herein include a method performed by awireless device. The method includes transmitting, to a radio networknode, a radio resource control, RRC, connection request that requeststhe establishment, re-establishment, or resumption of an RRC connectionand that indicates a type of core network to which the wireless deviceselects to connect.

In some embodiments, the RRC connection request indicates the type ofcore network to which the wireless device selects to connect based on atype of the RRC connection request. In this case, different possibletypes of RRC connection requests indicate different possible types ofcore networks to which the wireless device selects to connect.

In some embodiments, the method further comprises selecting a type ofcore network to which to connect and generating the RRC connectionrequest to indicate the selected type of core network.

In some embodiments, the method comprises transmitting the RRCconnection request without integrity protection and/or confidentialityprotection, and further comprises receiving a response to the RRCconnection request that is integrity protected and/or confidentialityprotected according to a security algorithm that depends on a type ofcore network indicated by the RRC connection request.

In some embodiments, the method comprises transmitting the RRCconnection request on a first type of signaling bearer that uses a firstprotocol stack, and further comprises receiving a response to the RRCconnection request on a second type of signaling bearer that usesdifferent possible protocol stacks depending on a type of core networkindicated by the RRC connection request. The different possible protocolstacks may for example have different versions of a packet dataconvergence protocol, PDCP.

In some embodiments, the method further comprises receiving a responseto the RRC connection request based on the type of core network to whichthe wireless device selects to connect. In one or more embodiments, forexample, receiving the response comprises determining, from differentpossible protocol stacks supported by the wireless device for receivinga response to the RRC connection request and based on the type of corenetwork to which the wireless device selects to connect, a protocolstack to use for receiving the response to the RRC connection request.The response to the RRC connection request may then be received usingthe determined protocol stack.

Embodiments also include a method performed by a wireless device. Themethod comprises transmitting, to a radio network node, a radio resourcecontrol, RRC, connection request that requests the establishment,re-establishment, or resumption of an RRC connection; and receiving aresponse to the RRC connection request based on a type of core networkto which the wireless device selects to connect.

Embodiments further include a method performed by a radio network node.The method comprises receiving, from a wireless device, a radio resourcecontrol, RRC, connection request that requests the establishment,re-establishment, or resumption of an RRC connection and that indicatesa type of core network to which the wireless device selects to connect.

In some embodiments, the RRC connection request indicates the type ofcore network to which the wireless device selects to connect based on atype of the RRC connection request. In this case, different possibletypes of RRC connection requests indicate different possible types ofcore networks to which the wireless device selects to connect.

In some embodiments, the method comprises receiving the RRC connectionrequest without integrity protection and/or confidentiality protection.In this case, the method may further comprise selecting, based on a typeof core network indicated by the RRC connection request, a securityalgorithm to use to apply integrity protection and/or confidentialityprotection to a response to the RRC connection request. The method maythen include applying integrity protection and/or confidentialityprotection to the response using the selected security algorithm, andtransmitting the response as integrity protected and/or confidentialityprotected.

In some embodiments, the method comprises receiving the RRC connectionrequest on a first type of signaling bearer that uses a first protocolstack. In this case, the method may further comprise selecting, based ona type of core network indicated by the RRC connection request and fromdifferent possible protocol stacks supported by the radio network node,a protocol stack to use for a second type of signaling bearer on whichto transmit a response to the RRC connection request. For example, thedifferent possible protocol stacks may have different versions of apacket data convergence protocol, PDCP. Regardless, the method may thencomprise transmitting the response to the RRC connection request on thesecond type of signaling bearer using the selected protocol stack.

In some embodiments, the method further comprises transmitting aresponse to the RRC connection request based on the type of core networkto which the wireless device selects to connect. In one or moreembodiments, for example, transmitting the response may comprisedetermining, from different possible protocol stacks supported by theradio network node for transmitting the response to the RRC connectionrequest and based on the type of core network to which the wirelessdevice selects to connect, a protocol stack to use for transmitting theresponse to the RRC connection request. The response to the RRCconnection may then be transmitted using the determined protocol stack.

Embodiments also include a method performed by a radio network node. Themethod comprises receiving, from a wireless device, a radio resourcecontrol, RRC, connection request that requests the establishment,re-establishment, or resumption of an RRC connection; and transmitting aresponse to the RRC connection request based on a type of core networkto which the wireless device selects to connect.

Embodiments moreover include a method performed by a radio network node.The method comprises receiving, from a wireless device, a radio resourcecontrol, RRC, connection request that requests the re-establishment orresumption of an RRC connection; responsive to the RRC connectionrequest, attempting to retrieve a context for the wireless device forre-establishing or resuming the RRC connection; and determining, basedon said attempting to retrieve the context for the wireless device, atype of core network to which the wireless device selects to connect.

In some embodiments, the method further comprises, before receiving theRRC connection request, releasing or suspending the RRC connection andstoring core network type information in the context for the wirelessdevice or in association with the context for the wireless device. Thiscore network type information may indicate the type of core network towhich the wireless device selected to connect for the RRC connection. Inthis case, determining the type of core network may comprise determiningthe type based on the core network type information stored in or inassociation with the retrieved context.

In some embodiments, the method further comprises, before receiving theRRC connection request, releasing or suspending the RRC connection andstoring the context for the wireless device in one of multiple differentpossible storage locations respectively associated with differentpossible types of core networks selectable by the wireless device. Inthis case, attempting to retrieve the context may comprise attempting toretrieve the context from one or more of the multiple different possiblestorage locations and determining the type of core network may comprisedetermining said type based on from which possible storage location thecontext is successfully retrieved.

In some embodiments, attempting to retrieve the context may compriseattempting to retrieve the context for the wireless device over one ormore of multiple different types of interfaces to another radio networknode respectively associated with different types of core networks, anddetermining the type of core network may comprise determining said typebased on over which type of interface the context is successfullyretrieved.

In some embodiments, the method may further comprise retrieving multiplecandidate contexts that are candidates for being the context for thewireless device, and determining which of the candidate contextscomprises the context for the wireless device based on which of thecandidate contexts includes a security token that is verified by theradio network node.

In some embodiments, the method may further comprise transmitting aresponse to the RRC connection request based on the type of core networkdetermined.

In some embodiments, the method may comprise receiving the RRCconnection request without integrity protection and/or confidentialityprotection. In one or more of these embodiments, the method may furthercomprise selecting, based on the type of core network determined, asecurity algorithm to use to apply integrity protection and/orconfidentiality protection to a response to the RRC connection request.The method may then include applying integrity protection and/orconfidentiality protection to the response using the selected securityalgorithm, and transmitting the response as integrity protected and/orconfidentiality protected.

In some embodiments, the method may comprise receiving the RRCconnection request on a first type of signaling bearer that uses a firstprotocol stack. In one or more of these embodiments, the method mayfurther comprise selecting, based on the type of core network determinedand from different possible protocol stacks supported by the radionetwork node, a protocol stack to use for a second type of signalingbearer on which to transmit a response to the RRC connection request,and transmitting the response to the RRC connection request on thesecond type of signaling bearer using the selected protocol stack. Inone embodiment, for example, the different possible protocol stacks havedifferent versions of a packet data convergence protocol, PDCP.

Embodiments also include corresponding apparatus, computer programs, andcomputer-readable storage mediums. For example, embodiments include awireless device. The wireless device is configured (e.g., viacommunication circuitry and processing circuitry) to transmit, to aradio network node, a radio resource control, RRC, connection requestthat requests the establishment, re-establishment, or resumption of anRRC connection and that indicates a type of core network to which thewireless device selects to connect.

A wireless device according to other embodiments is configured (e.g.,via communication circuitry and processing circuitry) to transmit, to aradio network node, a radio resource control, RRC, connection requestthat requests the establishment, re-establishment, or resumption of anRRC connection, and to receive a response to the RRC connection requestbased on a type of core network to which the wireless device selects toconnect.

Still other embodiments include a radio network node. The radio networknode is configured (e.g., via communication circuitry and processingcircuitry) to receive, from a wireless device, a radio resource control,RRC, connection request that requests the establishment,re-establishment, or resumption of an RRC connection and that indicatesa type of core network to which the wireless device selects to connect.

A radio network node according to other embodiments is configured (e.g.,via communication circuitry and processing circuitry) to receive, from awireless device, a radio resource control, RRC, connection request thatrequests the establishment, re-establishment, or resumption of an RRCconnection, and to transmit a response to the RRC connection requestbased on a type of core network to which the wireless device selects toconnect.

A radio network node according to yet other embodiments is configured(e.g., via communication circuitry and processing circuitry) to receive,from a wireless device, a radio resource control, RRC, connectionrequest that requests the re-establishment or resumption of an RRCconnection. Responsive to the RRC connection request, the radio networknode is configured to attempt to retrieve a context for the wirelessdevice for re-establishing or resuming the RRC connection. The radionetwork node is further configured to determine, based on saidattempting to retrieve the context for the wireless device, a type ofcore network to which the wireless device selects to connect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless communication system accordingto some embodiments.

FIG. 2 is a logic flow diagram of a method performed by a wirelessdevice according to some embodiments.

FIG. 3 is a logic flow diagram of a method performed by a wirelessdevice according to other embodiments.

FIG. 4 is a logic flow diagram of a method performed by a radio networknode according to some embodiments.

FIG. 5 is a logic flow diagram of a method performed by a radio networknode according to other embodiments.

FIG. 6 is a logic flow diagram of a method performed by a radio networknode according to still other embodiments.

FIG. 7 is a block diagram of a wireless device according to someembodiments.

FIG. 8 is a block diagram of a wireless device according to otherembodiments.

FIG. 9 is a block diagram of a radio network node according to someembodiments.

FIG. 10 is a block diagram of a radio network node according to otherembodiments.

FIG. 11 is a block diagram of a Next Generation Radio Access Network(NG-RAN) connected to a 5G Core Network (5G-CN) according to someembodiments.

FIG. 12 is a call flow diagram of a radio resource control (RRC)connection establishment procedure according to some embodiments.

FIG. 13A is a block diagram of a protocol stack for an eNB connected tothe Evolved Packet Core (EPC) according to some embodiments.

FIG. 13B is a block diagram of a protocol stack for an ng-eNB connectedto the 5G Core (5GC) according to some embodiments.

FIG. 14 is a call flow diagram of an RRC re-establishment/resumeprocedure according to some embodiments.

FIG. 15 is a logic flow diagram of a method performed by an eNB for RRCconnection re-establishment/resume according to some embodiments.

FIG. 16 is a block diagram of a wireless communication network accordingto some embodiments.

FIG. 17 is a block diagram of a user equipment according to someembodiments.

FIG. 18 is a block diagram of a virtualization environment according tosome embodiments.

FIG. 19 is a block diagram of a communication network with a hostcomputer according to some embodiments.

FIG. 20 is a block diagram of a host computer according to someembodiments.

FIG. 21 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment.

FIG. 22 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment.

FIG. 23 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment.

FIG. 24 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment.

DETAILED DESCRIPTION

FIG. 1 shows a wireless communication system 10 according to someembodiments. The system 10 includes a radio network node 12 (e.g., abase station) in a radio access network portion of the system 10. Thesystem 10 as shown also includes a wireless device 14 configured towirelessly communicate with the radio network node 12, e.g., forconnecting to a core network portion of the system 10. The radio networknode 12 according to some embodiments, for example, supports connectionwith multiple different types of core networks (CNs), two of which areshown as CN 16A (e.g., an Evolved Packet Core, EPC) and CN 16B (e.g.,5G-CN, 5GC). In some embodiments, the wireless device 14 correspondinglysupports connection with the different types of CNs 16A and 16B, suchthat the wireless device 14 is capable of selecting to connect to eithertype of CN 16A or 16B. This may distinguish the wireless device 14 fromanother type of wireless device that does not support connection withthe different types of CNs 16A and 16B.

In this regard, the wireless device 14 is configured to request theestablishment a radio resource control (RRC) connection 16 with theradio network node 12. The RRC connection 16 may be used for broadcastof system information, paging, transfer of non-access stratum (NAS)information, access stratum (AS) security configuration, transfer ofdevice radio access capability, measurement configuration and reporting,and/or mobility control. The RRC connection 16 in this regard may be thehighest layer in the control plane of the AS and may transfer messagesof the NAS (located above the RRC layer). With an RRC connection 16established, the radio network node 12 is able to allocate radioresources to the wireless device 14 and the device can correspondinglysend or receive data.

Establishment of the RRC connection 16 may involve configuring radiobearers between the radio network node 12 and the wireless device 14,configuring an AS security context, etc. The radio network node 12stores this and other information associated with the wireless device'sRRC connection 16 as a so-called context 14A for the wireless device 14.The context 14A for the wireless device 14 may therefore containinformation needed to establish and/or maintain the RRC connection 16,including for instance device state information, security information,device capability information, identities of the device-associatedlogical connection to the core network, and the like.

Release of the RRC connection 16 (e.g., after completion of datatransfer) correspondingly releases the device's context 14A at the radionetwork node 12, e.g., such that the radio network node 12 no longerstores that context 14A. Then, if and when the wireless device 14 needsanother RRC connection (e.g., for transfer of newly arrived data), thewireless device 14 must request re-establishment of an RRC connection.

In some embodiments, though, the radio network node 12 and wirelessdevice 14 support suspension of the RRC connection 16 as an alternativeto complete release of the RRC connection 16. When the RRC connection 16is suspended, the radio network node 12 preserves the context 14A forthe wireless device 14 rather than releasing it. This way, the wirelessdevice 14 can request resumption of the RRC connection 16 (e.g., byproviding the radio network node 12 with a Resume ID mapped to thecontext 14A) and thereby avoids AS security setup and RRCreconfiguration in each data transfer.

According to some embodiments, the wireless device 14 is configured totransmit an RRC connection request 18 to the radio network node 12. TheRRC connection request 18 requests the establishment, re-establishment,or resumption of an RRC connection 16. The RRC connection request 18 mayfor instance be an RRC connection establishment request, an RRCconnection re-establishment request, or an RRC connection resumerequest. In some embodiments, the request 18 may be referred to as MSG3in a random access procedure. Regardless, the radio network node 12 isconfigured to transmit a response 20 to the RRC connection request 18.The response 20 may for instance include information (e.g., a deviceidentity or a connection establishment cause) for establishing,re-establishing, or resuming the connection. Or, if the radio networknode 12 rejects the request 18, the response 20 may be a reject messagethat informs the wireless device 14 that the request 18 was rejected. Insome embodiments, the response 20 may be referred to as MSG4 in a randomaccess procedure.

In some embodiments, the radio network node 12 transmits the response 20based on a type of CN to which the wireless device 14 selects toconnect. For example, in one or more embodiments, the radio network node12 receives the RRC connection request 18 on a first type of signallingbearer 22A (e.g., SRB0) that uses a first protocol stack. And the radionetwork node 12 transmits the response 20 on a second type of signallingbearer 22B (e.g., SRB1) that uses different protocol stacks (e.g., asshown in FIGS. 13A and 13B) depending on a type of core network to whichthe wireless device 14 selects to connect. For instance, the differentprotocol stacks may have different versions of a packet data convergenceprotocol (PDCP) (e.g., LTE PDCP and NR-PDCP).

In this and other cases, then, the radio network node 12 may determine,from different possible protocol stacks supported by the radio networknode 12 for transmitting the response 20 to the RRC connection request18 and based on a type of core network to which the wireless device 14selects to connect, a protocol stack to use for transmitting theresponse 20 to the RRC connection request 18. The radio network node 12may then transmit the response 20 using the determined protocol stack.

Alternatively or additionally, in some embodiments, the radio networknode 12 receives the RRC connection request 18 without integrityprotection and/or confidentiality protection. And the radio network node12 transmits the response 20 to the RRC connection request 18 with theresponse 20 being integrity protected and/or confidentiality protectedaccording to a security algorithm that depends on a type of core networkto which the wireless device 14 selects to connect. For example, in someembodiments, the different protocol stacks mentioned above may usedifferent security algorithms (e.g., at the PDCP level). Regardless,then, the radio network node 12 may select, based on the type of corenetwork to which the wireless device 14 selects to connect, the securityalgorithm to use to apply integrity protection and/or confidentialityprotection to the response 20. The radio network node 12 may then applyintegrity protection and/or confidentiality protection to the response20 using the selected security algorithm, and transmit the response 20as integrity protected and/or confidentiality protected.

Although not shown, the wireless device 14 in some embodiments maytransmit another message, referred to as an acknowledgement message,that acknowledges the response 20 from the radio network node 12. Wherethe RRC connection request 18 requests the establishment of the RRCconnection 16, for example, the wireless device 14 may receive theresponse 20 in the form of an RRC Connection Setup message and thentransmit an RRC Connection Setup Complete message “(e.g., MSG5) whichacknowledges the response 20. Regardless, in one or more embodiments,the wireless device 14 may transmit the acknowledgement message based ona type of CN to which the wireless device 14 selects to connect. Forexample, in one or more embodiments, the wireless device 14 transmitsthe RRC connection request 18 on the first type of signalling bearer 22A(e.g., SRB0) that uses a first protocol stack. And the wireless device14 transmits the acknowledgement message on the second type ofsignalling bearer 22B (e.g., SRB1) that uses different protocol stacks(e.g., as shown in FIGS. 13A and 13B) depending on a type of corenetwork to which the wireless device 14 selects to connect. Forinstance, the different protocol stacks may have different versions of apacket data convergence protocol (PDCP) (e.g., LTE PDCP and NR-PDCP).

In this and other cases, then, the wireless device 14 may determine,from different possible protocol stacks supported by the wireless device14 for transmitting the acknowledgement message and based on a type ofcore network to which the wireless device 14 selects to connect, aprotocol stack to use for transmitting the acknowledgement message. Thewireless device 14 may then transmit the acknowledgement message usingthe determined protocol stack. Correspondingly, the radio network node12 may determine, from different possible protocol stacks supported bythe radio network node 12 for receiving the acknowledgement message andbased on a type of core network to which the wireless device 14 selectsto connect, a protocol stack to use for receiving the acknowledgementmessage.

Alternatively or additionally, in some embodiments, the wireless device14 transmits the RRC connection request 18 without integrity protectionand/or confidentiality protection. And the wireless device 14 transmitsthe acknowledgment message with the acknowledgment message beingintegrity protected and/or confidentiality protected according to asecurity algorithm that depends on a type of core network to which thewireless device 14 selects to connect. For example, in some embodiments,the different protocol stacks mentioned above may use different securityalgorithms (e.g., at the PDCP level). Regardless, then, the wirelessdevice 14 may select, based on the type of core network to which thewireless device 14 selects to connect, the security algorithm to use toapply integrity protection and/or confidentiality protection to theacknowledgment message. The wireless device 14 may then apply integrityprotection and/or confidentiality protection to the acknowledgmentmessage using the selected security algorithm, and transmit theacknowledgment message as integrity protected and/or confidentialityprotected.

Correspondingly, the radio network node 14 may receive the RRCconnection request 18 without integrity protection and/orconfidentiality protection. And the radio network node 14 receives theacknowledgment message with the acknowledgment message being integrityprotected and/or confidentiality protected according to a securityalgorithm that depends on a type of core network to which the wirelessdevice 14 selects to connect. For example, in some embodiments, thedifferent protocol stacks mentioned above may use different securityalgorithms (e.g., at the PDCP level). Regardless, then, the radionetwork node 14 may select, based on the type of core network to whichthe wireless device 14 selects to connect, the security algorithm withwhich to receive the acknowledgment message. The radio network node 14may then receive the acknowledgement message using the selected securityalgorithm.

In some embodiments, the wireless device 14 signals or otherwiseindicates to the radio network node 12 the type of core network (e.g.,16A or 16B) to which the wireless device 14 selects to connect (i.e.,the type of CN to which the wireless device 14 is connecting). Thewireless device 14 may for instance indicate the type of core network inthe RRC connection request 18. In other embodiments, the radio networknode 12 deduces or otherwise determines the type of core network, e.g.,based on the context 14A for the wireless device 14 or based on how thecontext 14A for the wireless device 14 is retrieved.

More particularly, the RRC connection request 18 in some embodimentsindicates a type of core network (e.g., 16A or 16B) to which thewireless device 14 selects to connect. For example, in some embodimentsas shown in FIG. 1, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect by thepresence or absence of a CN type field 18A in the RRC connection request18. The presence of the field 18A in the RRC connection request 18 mayindicate that the wireless device 14 selects to connect to a certaintype of core network (e.g., 5GC).

In other embodiments, the RRC connection request 18 indicates the typeof core network to which the wireless device 14 selects to connect basedon a type of the RRC connection request 18. In this case, differentpossible types of RRC connection requests indicate different possibletypes of core networks to which the wireless device 14 selects toconnect.

In still other embodiments, the RRC connection request 18 indicates thetype of core network to which the wireless device 14 selects to connectusing an identity for the wireless device 14 included in the RRCconnection request 18. This may mean that different possible identitiesare assigned to wireless devices based on a type of core network towhich the devices select to connect, e.g., based on active cooperationor coordination across different core network types, based on predefinedidentifier assignment rules, or the like.

In some embodiments, for example, where the RRC connection request 18 isan RRC connection re-establishment request that requests there-establishment of an RRC connection 16, the identity for the wirelessdevice 14 is a combination of a cell radio network temporary identifier(C-RNTI), a physical cell identity (PCI), and a security token. In otherembodiments where the RRC connection request 18 is an RRC connectionresume request that requests the resumption of an RRC connection 16, theidentity for the wireless device 14 is a resume identifier or aninactive state RNTI (I-RNTI) that identifies a wireless device context14A in an RRC inactive state.

No matter the particular nature of the identity for the wireless device14, though, the identity in some embodiments includes a bit or bitpattern that indicates the type of core network to which the wirelessdevice 14 selects to connect. For example, in one embodiment where thedevice identifier includes a C-RNTI, the first bit of the C-RNTI may beset to 0 to identify a wireless device that selects to connect to an EPCtype of CN, but may be set to 1 to identify a wireless device thatselects to connect to a 5GC type of CN. In other embodiments where thedevice identifier is a resume ID or an I-RNTI, the last bit of theidentifier may be set to 0 to identify a wireless device that selects toconnect to an EPC type of CN but may be set to 1 to identify a wirelessdevice that selects to connect to a 5GC type of CN.

In other embodiments where the radio network node 12 deduces orotherwise determines the type of core network, the radio network node 12may determine the type of core network based on its attempt to retrievethe context 14A for the wireless device 14, e.g., for re-establishing orresuming the RRC connection 16. In one embodiment, for example, theradio network node 14 stores core network type information in thecontext 14A for the wireless device 14 or in association with thecontext 14A, e.g., when establishing the RRC connection 16 initially butprior to release or suspension of that connection 16. The core networktype information indicates the type of core network to which thewireless device 14 selected to connect for the RRC connection 16. Thisway, the radio network node 12 may determine the type based on the corenetwork type information stored in or in association with the retrievedcontext 14A.

In still other embodiments, the radio network node 12 determines thetype of core network based on a location from which the context 14A isretrieved and/or based on an interface over which the context 14A isretrieved. For example, in some embodiments, before receiving the RRCconnection request 18, the radio network node 12 releases or suspendsthe RRC connection 16 and stores the context 14A for the wireless device14 in one of multiple different possible storage locations respectivelyassociated with different possible types of core networks selectable bythe wireless device 14. Later, when the wireless device 14 requests tore-establish or resume the RRC connection, the radio network node 12attempts to retrieve the context 14A from one or more of the multipledifferent possible storage locations, the radio network node 12determines the type of core network based on from which possible storagelocation the context 14A is successfully retrieved.

Alternatively, the radio network node 12 may attempt to retrieve thecontext 14A for the wireless device over one or more of multipledifferent types of interfaces to another radio network node (e.g., asource radio network node of a handover) respectively associated withdifferent types of core networks. In this case, the radio network node12 may determine the type of core network based on over which type ofinterface the context 14A is successfully retrieved.

In either case, if multiple candidate contexts are retrieved ascandidates for being the context 14A for the wireless device 14 (e.g.,which may happen if there is an identifier conflict or overlap), theradio network node 12 may determine which of the candidate contexts isthe context 14A for the wireless device 14 based on which of thecandidate contexts includes a security token (e.g., short I-MAC) that isverified by the radio network node 12.

Embodiments described above with respect to a type of core network towhich the wireless device 14 selects to connect may also be describedwith respect to a type of the wireless device 14. For example, differenttypes of wireless devices may be capable of connecting to differenttypes of core networks. Accordingly, in some embodiments, the radionetwork node 12 transmits the response 20 based on a type of thewireless device 14, e.g., as indicated by the RRC connection request 18and/or as determined from a context 14A for the wireless device. Stillother embodiments may be described with respect to a PDCP versionsupported by the wireless device 14.

In view of the above modifications and variations, FIG. 2 depicts amethod performed by a wireless device 14 in accordance with particularembodiments. The method includes transmitting, to a radio network node12, a radio resource control, RRC, connection request 18 that requeststhe establishment, re-establishment, or resumption of an RRC connection16 and that indicates a type of core network to which the wirelessdevice 14 selects to connect (Block 210). In some embodiments, themethod also comprises selecting a type of core network to which toconnect (Block 202) and generating the RRC connection request 18 toindicate the type of core network to which the wireless device 14selects to connect (Block 204). Alternatively or additionally, themethod may include receiving a response 20 to the RRC connection request18, e.g., based on the type of core network indicated by the RRCconnection request 18 (Block 220).

In some embodiments, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect by thepresence or absence of a field in the RRC connection request 18. Forexample, wherein the presence of the field in the RRC connection request18 may indicate that the wireless device 14 selects to connect to acertain type of core network.

In some embodiments, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect based ona type of the RRC connection request 18. For example, different possibletypes of RRC connection requests indicate different possible types ofcore networks to which the wireless device 14 selects to connect.

In some embodiments, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect using anidentity for the wireless device 14 included in the RRC connectionrequest 18. For example, where the RRC connection request 18 is an RRCconnection re-establishment request that requests the re-establishmentof an RRC connection 16, the identity for the wireless device 14 may bea combination of a cell radio network temporary identifier, C-RNTI, aphysical cell identity, PCI, and a security token. Or, where the RRCconnection request 18 is an RRC connection resume request that requeststhe resumption of an RRC connection 16, the identity for the wirelessdevice 14 may be a resume identifier or an inactive state RNTI, I-RNTI,that identifies a wireless device context in an RRC inactive state.

In either case, the identity for the wireless device 14 may include abit or bit pattern that indicates the type of core network to which thewireless device 14 selects to connect.

In some embodiments, the method further comprises selecting a type ofcore network to which to connect and generating the RRC connectionrequest 18 to indicate the selected type of core network.

In some embodiments, the method comprises transmitting the RRCconnection request 18 without integrity protection and/orconfidentiality protection. In this case, the method may furthercomprise receiving a response 20 to the RRC connection request 18 thatis integrity protected and/or confidentiality protected according to asecurity algorithm that depends on a type of core network indicated bythe RRC connection request 18.

In some embodiments, the method comprises transmitting the RRCconnection request 18 on a first type of signaling bearer that uses afirst protocol stack, and further comprises receiving a response 20 tothe RRC connection request 18 on a second type of signaling bearer thatuses different possible protocol stacks depending on a type of corenetwork indicated by the RRC connection request 18. For example, thedifferent possible protocol stacks may have different versions of apacket data convergence protocol, PDCP.

FIG. 3 depicts a method performed by a wireless device 14 in accordancewith other embodiments. The method includes transmitting, to a radionetwork node 12, a radio resource control, RRC, connection request 18that requests the establishment, re-establishment, or resumption of anRRC connection 16 (Block 310). The method also includes receiving aresponse 20 to the RRC connection request 18 based on a type of corenetwork to which the wireless device 14 selects to connect (Block 320).

In some embodiments, for example, such receiving comprises determining,from different possible protocol stacks supported by the wireless device14 for receiving a response 20 to the RRC connection request 18 andbased on the type of core network to which the wireless device 14selects to connect, a protocol stack to use for receiving the response20 to the RRC connection request 18. The method may then comprisereceiving the response 20 to the RRC connection request 18 using thedetermined protocol stack.

Alternatively or additionally, the method comprises transmitting the RRCconnection request 18 without integrity protection and/orconfidentiality protection; and receiving the response 20 to the RRCconnection request 18 with the response being integrity protected and/orconfidentiality protected according to a security algorithm that dependson a type of core network to which the wireless device 14 selects toconnect.

Alternatively or additionally, the method comprises transmitting the RRCconnection request 18 on a first type of signaling bearer 22A that usesa first protocol stack, and receiving the response 20 to the RRCconnection request 18 on a second type of signaling bearer 22B that usesthe different possible protocol stacks depending on a type of corenetwork to which the wireless device 14 selects to connect. In oneembodiment, for example, the different possible protocol stacks havedifferent versions of a packet data convergence protocol, PDCP.

FIG. 4 depicts a method performed by a radio network node 12 (e.g., abase station) in accordance with other particular embodiments. Themethod includes receiving, from a wireless device 14, a radio resourcecontrol, RRC, connection request 18 that requests the establishment,re-establishment, or resumption of an RRC connection 16 and thatindicates a type of core network to which the wireless device 14 selectsto connect (Block 410). The method in some embodiments may also comprisedetermining (e.g., after or from the RRC connection request 18) the typeof core network to which the wireless device 14 selects to connect(Block 420). Alternatively or additionally, the method may comprisetransmitting a response 20 to the RRC connection request 18, e.g., basedon the determined type of core network to which the wireless device 14selects to connect (Block 430).

In some embodiments, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect by thepresence or absence of a field in the RRC connection request 18. Forexample, wherein the presence of the field in the RRC connection request18 may indicate that the wireless device 14 selects to connect to acertain type of core network.

In some embodiments, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect based ona type of the RRC connection request 18. For example, different possibletypes of RRC connection requests indicate different possible types ofcore networks to which the wireless device 14 selects to connect.

In some embodiments, the RRC connection request 18 indicates the type ofcore network to which the wireless device 14 selects to connect using anidentity for the wireless device 14 included in the RRC connectionrequest 18. For example, where the RRC connection request 18 is an RRCconnection re-establishment request that requests the re-establishmentof an RRC connection 16, the identity for the wireless device 14 may bea combination of a cell radio network temporary identifier, C-RNTI, aphysical cell identity, PCI, and a security token. Or, where the RRCconnection request 18 is an RRC connection resume request that requeststhe resumption of an RRC connection 16, the identity for the wirelessdevice 14 may be a resume identifier or an inactive state RNTI, I-RNTI,that identifies a wireless device context in an RRC inactive state.

In either case, the identity for the wireless device 14 may include abit or bit pattern that indicates the type of core network to which thewireless device 14 selects to connect.

In some embodiments, the method comprises receiving the RRC connectionrequest 18 without integrity protection and/or confidentialityprotection. In one or more such embodiments, the method may furthercomprise selecting, based on a type of core network indicated by the RRCconnection request 18, a security algorithm to use to apply integrityprotection and/or confidentiality protection to a response 20 to the RRCconnection request 18. The method may then comprise applying integrityprotection and/or confidentiality protection to the response 20 usingthe selected security algorithm, and transmitting the response 20 asintegrity protected and/or confidentiality protected.

Alternatively or additionally, the method may comprise receiving the RRCconnection request 18 on a first type of signaling bearer 22A that usesa first protocol stack. In one or more such embodiments, the method mayfurther comprise selecting, based on a type of core network indicated bythe RRC connection request 18 and from different possible protocolstacks supported by the radio network node, 12 a protocol stack to usefor a second type of signaling bearer 22B on which to transmit aresponse 20 to the RRC connection request 18. In one embodiments, forexample, the different possible protocol stacks have different versionsof a packet data convergence protocol, PDCP. Regardless, the method maythen comprise transmitting the response 20 to the RRC connection request18 on the second type of signaling bearer 22B using the selectedprotocol stack.

FIG. 5 depicts a method performed by a radio network node 12 (e.g., abase station) in accordance with yet other particular embodiments. Themethod includes receiving, from a wireless device 14, a radio resourcecontrol, RRC, connection request 18 that requests the establishment,re-establishment, or resumption of an RRC connection 16 (Block 510). Themethod also includes transmitting a response 20 to the RRC connectionrequest 18 based on a type of core network to which the wireless device14 selects to connect (Block 520).

In some embodiments, for example, such transmitting comprisesdetermining, from different possible protocol stacks supported by theradio network node 12 for transmitting the response 20 to the RRCconnection request 18 and based on a type of core network to which thewireless device 14 selects to connect, a protocol stack to use fortransmitting the response 20 to the RRC connection request 18. Themethod may then comprise transmitting the response 20 to the RRCconnection request 18 using the determined protocol stack.

Alternatively or additionally, the method comprises receiving the RRCconnection request 18 without integrity protection and/orconfidentiality protection. In this case, the method may comprisetransmitting the response 20 to the RRC connection request 18 with theresponse 20 being integrity protected and/or confidentiality protectedaccording to a security algorithm that depends on a type of core networkto which the wireless device 14 selects to connect.

Alternatively or additionally, the method comprises receiving the RRCconnection request 18 on a first type of signaling bearer 22A that usesa first protocol stack. In this case, the method may further compriseselecting, based on a type of core network indicated by the RRCconnection request 18 and from different possible protocol stackssupported by the radio network node 12, a protocol stack to use for asecond type of signaling bearer 22B on which to transmit a response 20to the RRC connection request 18. In one embodiment, for example, thedifferent possible protocol stacks have different versions of a packetdata convergence protocol, PDCP. Regardless, the method may thencomprise transmitting the response 20 to the RRC connection request 18on the second type of signaling bearer 22B using the selected protocolstack.

FIG. 6 depicts a method performed by a radio network node 12 (e.g., abase station) in accordance with still other particular embodiments. Themethod includes receiving, from a wireless device 14, a radio resourcecontrol, RRC, connection request 18 that requests the re-establishmentor resumption of an RRC connection 16 (Block 610). The method alsoincludes, responsive to the RRC connection request 18, attempting toretrieve a context 14A for the wireless device 14 for re-establishing orresuming the RRC connection 16 (Block 620). The method further includesdetermining, based on said attempting to retrieve the context 14A forthe wireless device 14, a type of core network to which the wirelessdevice 14 selects to connect (Block 630).

In some embodiments, the method further comprises transmitting aresponse 20 to the RRC connection request 18, e.g., based on thedetermined type of core network to which the wireless device 14 selectsto connect (Block 640).

In some embodiments, the method further comprises, before receiving theRRC connection request 18, releasing or suspending the RRC connection 16and storing core network type information in the context 14A for thewireless device 14 or in association with the context 14A for thewireless device 14. The core network type information may indicate thetype of core network to which the wireless device 14 selected to connectfor the RRC connection 16. In this case, determining the type of corenetwork may comprise determining said type based on the core networktype information stored in or in association with the retrieved context14A.

In other embodiments, the method may further comprise, before receivingthe RRC connection request 18, releasing or suspending the RRCconnection 16 and storing the context 14A for the wireless device 14 inone of multiple different possible storage locations respectivelyassociated with different possible types of core networks selectable bythe wireless device 14. In this case, said attempting may compriseattempting to retrieve the context 14A from one or more of the multipledifferent possible storage locations. Accordingly, determining the typeof core network may comprise determining said type based on from whichpossible storage location the context 14A is successfully retrieved.

In yet other embodiments, attempting to retrieve the context 14A maycomprise attempting to retrieve the context 14A for the wireless device14 over one or more of multiple different types of interfaces to anotherradio network node respectively associated with different types of corenetworks. In this case, determining the type of core network maycomprise determining said type based on over which type of interface thecontext 14A is successfully retrieved.

In some embodiments, the method may further comprise retrieving multiplecandidate contexts that are candidates for being the context 14A for thewireless device 14. In this case, the method may further comprisedetermining which of the candidate contexts comprises the context 14Afor the wireless device 14 based on which of the candidate contextsincludes a security token that is verified by the radio network node 12.

In some embodiments, the method comprises receiving the RRC connectionrequest 18 without integrity protection and/or confidentialityprotection. The method may then further comprise selecting, based on thetype of core network determined, a security algorithm to use to applyintegrity protection and/or confidentiality protection to a response 20to the RRC connection request 18. The method may then comprise applyingintegrity protection and/or confidentiality protection to the response20 using the selected security algorithm, and transmitting the response20 as integrity protected and/or confidentiality protected.

In some embodiments, the method comprises receiving the RRC connectionrequest 18 on a first type of signaling bearer 22A that uses a firstprotocol stack. In this case, the method may further comprise selecting,based on the type of core network determined and from different possibleprotocol stacks supported by the radio network node 12, a protocol stackto use for a second type of signaling bearer 22B on which to transmit aresponse 20 to the RRC connection request 18. For example, the differentpossible protocol stacks may have different versions of a packet dataconvergence protocol, PDCP. Regardless, the method may then comprisetransmitting the response 20 to the RRC connection request 18 on thesecond type of signaling bearer 22B.

Note that the apparatuses described above may perform the methods hereinand any other processing by implementing any functional means, modules,units, or circuitry. In one embodiment, for example, the apparatusescomprise respective circuits or circuitry configured to perform thesteps shown in the method figures. The circuits or circuitry in thisregard may comprise circuits dedicated to performing certain functionalprocessing and/or one or more microprocessors in conjunction withmemory. For instance, the circuitry may include one or moremicroprocessor or microcontrollers, as well as other digital hardware,which may include digital signal processors (DSPs), special-purposedigital logic, and the like. The processing circuitry may be configuredto execute program code stored in memory, which may include one orseveral types of memory such as read-only memory (ROM), random-accessmemory, cache memory, flash memory devices, optical storage devices,etc. Program code stored in memory may include program instructions forexecuting one or more telecommunications and/or data communicationsprotocols as well as instructions for carrying out one or more of thetechniques described herein, in several embodiments. In embodiments thatemploy memory, the memory stores program code that, when executed by theone or more processors, carries out the techniques described herein.

FIG. 7 for example illustrates a wireless device 700 (e.g., wirelessdevice 14) as implemented in accordance with one or more embodiments. Asshown, the wireless device 700 includes processing circuitry 710 andcommunication circuitry 720. The communication circuitry 720 (e.g.,radio circuitry) is configured to transmit and/or receive information toand/or from one or more other nodes, e.g., via any communicationtechnology. Such communication may occur via one or more antennas thatare either internal or external to the wireless device 700. Theprocessing circuitry 710 is configured to perform processing describedabove (e.g., in FIGS. WW1 and WW2), such as by executing instructionsstored in memory 730. The processing circuitry 710 in this regard mayimplement certain functional means, units, or modules.

FIG. 8 illustrates a schematic block diagram of a wireless device 800(e.g., wireless device 14) in a wireless network according to stillother embodiments (for example, the wireless network shown in FIG. 16).As shown, the wireless device 800 implements various functional means,units, or modules, e.g., via the processing circuitry 710 in FIG. 7and/or via software code. These functional means, units, or modules,e.g., for implementing the method(s) herein, include for instance atransmitting unit 810 for transmitting an RRC connection request 18 asdescribed above. Alternatively or additionally, a receiving unit 820 maybe included for receiving a response 20 to the RRC connection request 18as described above.

FIG. 9 illustrates a radio network node 900 (e.g., radio network node12) as implemented in accordance with one or more embodiments. As shown,the radio network node 900 includes processing circuitry 910 andcommunication circuitry 920. The communication circuitry 920 isconfigured to transmit and/or receive information to and/or from one ormore other nodes, e.g., via any communication technology. The processingcircuitry 910 is configured to perform processing described above (e.g.,in FIGS. WW3, WW4, and/or WW5), such as by executing instructions storedin memory 930. The processing circuitry 910 in this regard may implementcertain functional means, units, or modules.

FIG. 10 illustrates a schematic block diagram of a radio network node1000 (e.g., radio network node 12) in a wireless network according tostill other embodiments (for example, the wireless network shown in FIG.16). As shown, the radio network node 1000 implements various functionalmeans, units, or modules, e.g., via the processing circuitry 910 in FIG.9 and/or via software code. These functional means, units, or modules,e.g., for implementing the method(s) herein, include for instance areceiving unit 1010 receiving, from a wireless device, a radio resourcecontrol, RRC, connection request 18 that requests the re-establishmentor resumption of an RRC connection 16. In some embodiments, the RRCconnection request 18 indicates a type of core network to which thewireless device 14 selects to connect. Alternatively or additionally, atransmitting unit 1020 may be included for transmitting a response 20 tothe RRC connection request 18 based on a type of core network to whichthe wireless device 14 selects to connect. Alternatively oradditionally, a context retrieval unit 1030 may be included for,responsive to the RRC connection request 18, attempting to retrieve acontext 14A for the wireless device 14 for re-establishing or resumingthe RRC connection and a determining unit 1040 may be included fordetermining, based on said attempting to retrieve the context 14A forthe wireless device 14, a type of core network to which the wirelessdevice 14 selects to connect.

Those skilled in the art will also appreciate that embodiments hereinfurther include corresponding computer programs.

A computer program comprises instructions which, when executed on atleast one processor of an apparatus, cause the apparatus to carry outany of the respective processing described above. A computer program inthis regard may comprise one or more code modules corresponding to themeans or units described above.

Embodiments further include a carrier containing such a computerprogram. This carrier may comprise one of an electronic signal, opticalsignal, radio signal, or computer readable storage medium.

In this regard, embodiments herein also include a computer programproduct stored on a non-transitory computer readable (storage orrecording) medium and comprising instructions that, when executed by aprocessor of an apparatus, cause the apparatus to perform as describedabove.

Embodiments further include a computer program product comprisingprogram code portions for performing the steps of any of the embodimentsherein when the computer program product is executed by a computingdevice. This computer program product may be stored on a computerreadable recording medium.

Although embodiments herein have been described with respect to an RRCconnection 16, embodiments herein are extendable to other types ofconnections. Some embodiments for example extend to any type of controlplane connection or signalling connection between the wireless device 14and the radio network node 12.

Additional embodiments will now be described. At least some of theseembodiments may be described as applicable in certain contexts and/orwireless network types for illustrative purposes, but the embodimentsare similarly applicable in other contexts and/or wireless network typesnot explicitly described.

The 5G system defined by 3GPP Rel-15 includes both a new radio accessnetwork (NG-RAN) and a new core network (5G-CN).

Similar to the Evolved Universal Terrestrial Radio Access Network(E-UTRAN), the NG-RAN as shown in FIG. 11 uses a flat architecture andconsists of base stations, called gNBs, which are inter-connected viathe Xn-interface and towards the core network by the N2/N3-interface.The gNB in turn supports one or more cells which provides the radioaccess to the UE. The radio access technology (called next radio, NR) isOrthogonal Frequency Division Multiplex (OFDM) based like in LTE andoffers high data transfer speeds and low latency.

It is expected that NR will be rolled out gradually on top of the legacyLTE network starting in areas where high data traffic is expected. Thismeans that NR coverage will be limited in the beginning and users mustmove between NR and LTE as they go in and out of coverage. To supportfast mobility between NR and LTE and avoid change of core network, LTEeNBs will also connect to the 5G-CN and support the Xn interface asshown in FIG. 11. An eNB connected to 5GC is called a next generationeNB (ng-eNB) and is considered part of the NG-RAN.

An eNB may at the same time be connected to both EPC (i.e. the eNB ispart of legacy E-UTRAN) and 5GC (i.e. the eNB is an ng-eNB belonging tong-RAN). The term eNB as used herein may refer to both an eNB and ng-eNBunless there is specific need to distinguish between the two.

FIG. 12 shows the RRC connection setup procedure for LTE/5GC. Theprocedure includes the UE transmitting a random access preamble (MSG1)to the eNB, e.g., responsive to receiving paging from the eNB. The eNBtransmits a random access response (MSG2) to the UE. The UE thentransmits an RRC connection request (MSG3) to the eNB and receives inresponse an RRC connection setup (MSG4). The UE next transmits an RRCconnection setup complete message (MSG5) to the eNB. Accordingly, theRRC connection setup procedure in LTE/5GC is almost identical to the onein LTE/EPC and in particular the RRC messages and message sequence arethe same. The main difference is in MSG5 (RRC Connection Setup Complete)which includes an indication that the UE is connecting to 5GC instead ofEPC. In the same way as in LTE/EPC, MSG3 and MSG4 are sent on SignalingRadio Bearer 0 (SRB0) and MSG5 is sent on Signaling Radio Bearer 1(SRB1).

As noted earlier, an eNB may at the same time be connected to both EPCand 5GC. Thus, the eNB will receive RRC connection establishmentrequests from both LTE/EPC and LTE/5GC UEs. Furthermore, the eNBheretofore may not be able to distinguish between the two types UEs(namely, a UE connected to LTE/EPC and a UE connected to LTE/5GC) untilthe “LTE connected to 5GC indication” is received in MSG5.

The fact that the eNB is heretofore not able to determine the UE type(or, in other words, the type of core network to which the UE isconnecting) until after MSG5 causes a problem for SRB1 which uses aslightly different protocol stack in LTE/5GC than in LTE/EPC. As can beseen in FIG. 13A, SRB1 in LTE/EPC uses the LTE version of the PDCPlayer, whereas as seen in FIG. 13B SRB1 in LTE/5GC uses the NR versionof PDCP. This means that when MSG5 is sent by the UE on SRB1, the eNBheretofore does not know whether it should receive it using LTE PDCP orNR PDCP. To solve this problem, LTE/5GC could use LTE PDCP for SRB1initially and then switch to NR PDCP after MSG5 is sent.

A similar PDCP version issue arises also for RRC connectionre-establishment and RRC connection resume in LTE/5GC.

FIG. 14 shows the RRC connection re-establishment and RRC connectionresume procedures for LTE/5GC. The RRC connectionre-establishment/resume procedure in LTE/5GC is very similar to the onein LTE/EPC and the RRC messages and message sequences are the same. Inthe RRC connection re-establishment/resume procedure, MSG3 is sent onSRB0 and MSG4 and MSG5 are sent on SRB1. Furthermore, both intra- andinter-eNB re-establishment/resume is supported. In case of inter-eNBre-establishment/resume, the target eNB fetches the UE context from thesource eNB using the UE ID included in the MSG3 (containing the RRCconnection re-establishment/resume request).

When the eNB receives MSG3 (containing the RRC connectionre-establishment/resume request) on SRB0, it heretofore is not yet beable to determine the UE type. This means that the eNB heretofore doesnot know which PDCP version to use when it sends MSG4 on SRB1.

One potential solution to handle the PDCP version issue at RRCconnection re-establishment/RRC connection resume would be to revert toLTE PDCP for SRB1 at the start of the procedure and then switch back toNR PDCP after MSG5 is sent. Apart from causing unnecessary switchingbetween PDCP versions, the problem with this approach is that itrequires the UE to change from an 5GS to EPS security algorithm. This isbecause, unlike RRC connection establishment, MSG4 is sent protected atRRC connection re-establishment/RRC connection resume and the securityalgorithm used is dependent on the PDCP layer. Currently, changing thesecurity algorithm would not be much of a problem, since the securityalgorithms are currently identical in EPS and 5GS. But it couldpotentially become a problem in the future if different securityalgorithms are introduced in EPS and 5GS.

Certain aspects of the present disclosure and their embodiments mayprovide solutions to these or other challenges. When a UE re-establishesor resumes an RRC connection, the eNB according to some embodimentsdetermines the UE type (also referred to as CN type to which the UE isconnecting) already at MSG3 in the RRC connectionre-establishment/resume procedure. This may be done either by (1)indicating the UE type in MSG3, or (2) by determining the UE type basedon UE identity included in MSG3, or (3) by determining the UE type fromthe retrieved UE context. According to some embodiments, this avoids theUE having to switch from NR PDCP to LTE PDCP.

Certain embodiments may provide one or more of the following technicaladvantage(s). Some embodiments allow an LTE/5GC UE to re-establish orresume an RRC connection without having to switch PDCP versions forSRB1. This in turn has one or more of the following advantages: (i)Simplifies UE implementation as well as the 3GPP specification; (ii)Features available in NR PDCP but not in LTE PDCP can be used alsoduring RRC connection re-establishment/resume; and/or (iii) a UE is notrequired to switch between EPS and 5GS security algorithms, which meansthat the EPS and 5GS security algorithms can evolve independentlywithout requiring a mapping between two sets of algorithms.

Note that the below embodiments may refer to “UE type”. The UE type asused below may be used interchangeably with CN type used above,depending on context. The UE type may for instance indicate a type of CNto which a UE selects (or is capable of selecting) to connect, e.g., todistinguish that UE from another UE which selects (or is capable ofselecting) to connect to a different type of CN.

To avoid switching from NR PDCP to LTE PDCP when a UE re-establishes orresumes an RRC connection, the eNB according to some embodimentsdetermines the UE type (and thereby the PDCP version to use) already atMSG3 in the RRC connection re-establishment/resume procedure. This isdone either by (1) indicating the UE type in MSG3, or (2) by determiningthe UE type based on UE identity included in MSG3, or (3) by determiningthe UE type from the retrieved UE context. Each solution is described inmore detail below.

In the first solution, the LTE/5GC UE includes an indication in MSG3which allows the eNB to distinguish the UE from a legacy LTE/EPC UE. Theindication can either be explicit such as a flag indicating the UE type,or it can be implicit based on, e.g., the message type orpresence/absence of certain parameter.

The second solution avoids any changes to MSG3 and instead the eNBdetermines the UE type based on the UE identity included in MSG3. Thisis done by coordinating the allocation of the UE identity in E-UTRAN andNG-RAN so that the RAN type can be determined from the UE identity. Thedetails differ between resume and re-establishment since the UE identityis constructed differently for these procedures. For re-establishment,the UE ID is comprised of C-RNTI, Physical Cell Identity (PCI) andSecurity Token (Short MAC-I). For resume, the UE ID is comprised of theResume ID (LTE/EPC) or I-RNTI (LTE/5GC).

In case of re-establishment the only part of the UE ID that can be setby the eNB is the C-RNTI. This means that to be able to distinguish theUE type based on UE identity, all eNBs would need to allocate differentC-RNTIs for UEs connected to EPC and 5GC. For example, the first bit ofC-RNTI could be set to 0 for LTE/EPC UEs and to 1 for LTE/5GC UEs.

As can be seen, a different UE ID is used for the resume procedure inLTE/EPC and LTE/5GC (Resume ID and I-RNTI, respectively). However, ifthe Resume ID and I-RNTI are of the same length and are included in thesame field in the RRC connection resume request, the eNB will still notbe able to distinguish between them. One way to accomplish this is tocoordinate the allocation of the Resume ID and I-RNTI between E-UTRANand NG-RAN. For example, the last bit of the Resume ID could always beset to 0 whereas the last bit of the I-RNTI would be set to 1. The sameis true if the I-RNTI and Resume ID are of different lengths and theI-RNTI and/or Resume ID are truncated to the same length and included inthe same field in MSG3.

In case the I-RNTI size is smaller than the Resume ID, it still wouldhave to fit in the Resume ID space in LTE to support legacy MSG3structure. So, the remaining bits could be filled with a filler bitpattern which indicates that it is an I-RNTI instead of a Resume ID. Inthis case, E-UTRAN would need to ensure that the particular filler bitpattern is not used when the Resume IDs are allocated.

In the third solution, the eNB determines the UE type based on the UEcontext. In case of intra-eNB re-establishment/resume, the eNB can e.g.store the UE type together with the UE context or it can store the UEcontexts for the UE types in different locations. In case of inter-eNBre-establishment/resume, the interface used to retrieve the context isdependent on the UE type (X2 in E-UTRAN and Xn in NG-RAN). The eNB cantherefore determine the UE type by trying both interfaces (eithersequentially or in parallel) to see which one succeeds.

Due to an identity collision (e.g. same I-RNTI/Resume ID used in E-UTRANand NG-RAN), it may happen that two UE contexts are found, i.e. one forE-UTRAN and one for NGRAN. However, in this case the correct UE contextcan be determined when the security token is verified. For example, inthe case of inter-eNB resume, the context fetch procedure will stillonly succeed for one of the interfaces since the source eNB will detectthe “false” UE context when it verifies the security token (the shortMAC-I from MSG3).

FIG. 15 shows a process for RRC connection re-establishment or resumeaccording to some embodiments. As shown, the eNB first receives MSG3 inthe form of an RRC connection re-establishment/resume request (Block1500). The eNB then determines the UE type (i.e., an LTE/EPC UE or anLTE/5GC UE) (Block 1510). Determining the UE type may differ inimplementation depending on which solution above is used. If the UE isan LTE/5GC UE (Yes at Block 1520), the eNB applies the NR PDCP for SRB1(Block 1530). If the UE is not an LTE/5GC UE (No at Block 1520), the eNBapplies the LTE PDCP for SRB1 (Block 1540). Either way, the eNBcontinues with the RRC connection re-establishment/resume procedure(Block 1550).

The discussion above has only considered the situation where the gNB isconnected to both EPC and 5GC. Some embodiments also consider whathappens when a LTE/5GC UE attempts to re-establish or resume an RRCconnection in an eNB that only supports EPC. In this case, the UEaccording to a first solution moves to RRC_IDLE state and performs aregular RRC connection setup when it discovers that the selected cell isan EPC-only cell.

According to a second solution, the UE goes ahead with the RRCconnection re-establishment/resume. In option ‘a’, the eNB rejects theUE on SRB0 (since the X2 UE context fetch procedure fails) which causesthe UE to move to RRC_IDLE and perform a normal connection setup. Inoption ‘b’, the eNB manages to retrieve the UE context over X2, butsince the eNB is LTE/5GC unaware, LTE PDCP is used for SRB1. In option‘c’, the eNB manages to retrieve the UE context over X2 and is awarethat the UE is a LTE/5GC UE and therefore applies NR PDCP for SRB1. Notethat option ‘b’ and ‘c’ both require that an NG-RAN UE context can betransformed into an E-UTRAN context and fetched over X2.

Although the subject matter described herein may be implemented in anyappropriate type of system using any suitable components, theembodiments disclosed herein are described in relation to a wirelessnetwork, such as the example wireless network illustrated in FIG. 16.For simplicity, the wireless network of FIG. 16 only depicts network1606, network nodes 1660 and 1660 b, and WDs 1610, 1610 b, and 1610 c.In practice, a wireless network may further include any additionalelements suitable to support communication between wireless devices orbetween a wireless device and another communication device, such as alandline telephone, a service provider, or any other network node or enddevice. Of the illustrated components, network node 1660 and wirelessdevice (WD) 1610 are depicted with additional detail. The wirelessnetwork may provide communication and other types of services to one ormore wireless devices to facilitate the wireless devices' access toand/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), Narrowband Internet of Things (NB-IoT), and/or other suitable 2G,3G, 4G, or 5G standards; wireless local area network (WLAN) standards,such as the IEEE 802.11 standards; and/or any other appropriate wirelesscommunication standard, such as the Worldwide Interoperability forMicrowave Access (WMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network 1606 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 1660 and WD 1610 comprise various components described inmore detail below. These components work together in order to providenetwork node and/or wireless device functionality, such as providingwireless connections in a wireless network. In different embodiments,the wireless network may comprise any number of wired or wirelessnetworks, network nodes, base stations, controllers, wireless devices,relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs(eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based onthe amount of coverage they provide (or, stated differently, theirtransmit power level) and may then also be referred to as femto basestations, pico base stations, micro base stations, or macro basestations. A base station may be a relay node or a relay donor nodecontrolling a relay. A network node may also include one or more (orall) parts of a distributed radio base station such as centralizeddigital units and/or remote radio units (RRUs), sometimes referred to asRemote Radio Heads (RRHs). Such remote radio units may or may not beintegrated with an antenna as an antenna integrated radio. Parts of adistributed radio base station may also be referred to as nodes in adistributed antenna system (DAS). Yet further examples of network nodesinclude multi-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MM Es), O&M nodes, OSS nodes,SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 16, network node 1660 includes processing circuitry 1670, devicereadable medium 1680, interface 1690, auxiliary equipment 1684, powersource 1686, power circuitry 1687, and antenna 1662. Although networknode 1660 illustrated in the example wireless network of FIG. 16 mayrepresent a device that includes the illustrated combination of hardwarecomponents, other embodiments may comprise network nodes with differentcombinations of components. It is to be understood that a network nodecomprises any suitable combination of hardware and/or software needed toperform the tasks, features, functions and methods disclosed herein.Moreover, while the components of network node 1660 are depicted assingle boxes located within a larger box, or nested within multipleboxes, in practice, a network node may comprise multiple differentphysical components that make up a single illustrated component (e.g.,device readable medium 1680 may comprise multiple separate hard drivesas well as multiple RAM modules).

Similarly, network node 1660 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 1660comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeB's.In such a scenario, each unique NodeB and RNC pair, may in someinstances be considered a single separate network node. In someembodiments, network node 1660 may be configured to support multipleradio access technologies (RATs). In such embodiments, some componentsmay be duplicated (e.g., separate device readable medium 1680 for thedifferent RATs) and some components may be reused (e.g., the sameantenna 1662 may be shared by the RATs). Network node 1660 may alsoinclude multiple sets of the various illustrated components fordifferent wireless technologies integrated into network node 1660, suchas, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wirelesstechnologies. These wireless technologies may be integrated into thesame or different chip or set of chips and other components withinnetwork node 1660.

Processing circuitry 1670 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 1670 may include processinginformation obtained by processing circuitry 1670 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedin the network node, and/or performing one or more operations based onthe obtained information or converted information, and as a result ofsaid processing making a determination.

Processing circuitry 1670 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 1660 components, such as device readable medium 1680, network node1660 functionality. For example, processing circuitry 1670 may executeinstructions stored in device readable medium 1680 or in memory withinprocessing circuitry 1670. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 1670 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 1670 may include one or moreof radio frequency (RF) transceiver circuitry 1672 and basebandprocessing circuitry 1674. In some embodiments, radio frequency (RF)transceiver circuitry 1672 and baseband processing circuitry 1674 may beon separate chips (or sets of chips), boards, or units, such as radiounits and digital units. In alternative embodiments, part or all of RFtransceiver circuitry 1672 and baseband processing circuitry 1674 may beon the same chip or set of chips, boards, or units

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 1670executing instructions stored on device readable medium 1680 or memorywithin processing circuitry 1670. In alternative embodiments, some orall of the functionality may be provided by processing circuitry 1670without executing instructions stored on a separate or discrete devicereadable medium, such as in a hard-wired manner. In any of thoseembodiments, whether executing instructions stored on a device readablestorage medium or not, processing circuitry 1670 can be configured toperform the described functionality. The benefits provided by suchfunctionality are not limited to processing circuitry 1670 alone or toother components of network node 1660, but are enjoyed by network node1660 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1680 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,volatile, non-transitory device readable and/or computer-executablememory devices that store information, data, and/or instructions thatmay be used by processing circuitry 1670. Device readable medium 1680may store any suitable instructions, data or information, including acomputer program, software, an application including one or more oflogic, rules, code, tables, etc. and/or other instructions capable ofbeing executed by processing circuitry 1670 and, utilized by networknode 1660. Device readable medium 1680 may be used to store anycalculations made by processing circuitry 1670 and/or any data receivedvia interface 1690. In some embodiments, processing circuitry 1670 anddevice readable medium 1680 may be considered to be integrated.

Interface 1690 is used in the wired or wireless communication ofsignalling and/or data between network node 1660, network 1606, and/orWDs 1610. As illustrated, interface 1690 comprises port(s)/terminal(s)1694 to send and receive data, for example to and from network 1606 overa wired connection. Interface 1690 also includes radio front endcircuitry 1692 that may be coupled to, or in certain embodiments a partof, antenna 1662. Radio front end circuitry 1692 comprises filters 1698and amplifiers 1696. Radio front end circuitry 1692 may be connected toantenna 1662 and processing circuitry 1670. Radio front end circuitrymay be configured to condition signals communicated between antenna 1662and processing circuitry 1670. Radio front end circuitry 1692 mayreceive digital data that is to be sent out to other network nodes orWDs via a wireless connection. Radio front end circuitry 1692 mayconvert the digital data into a radio signal having the appropriatechannel and bandwidth parameters using a combination of filters 1698and/or amplifiers 1696. The radio signal may then be transmitted viaantenna 1662. Similarly, when receiving data, antenna 1662 may collectradio signals which are then converted into digital data by radio frontend circuitry 1692. The digital data may be passed to processingcircuitry 1670. In other embodiments, the interface may comprisedifferent components and/or different combinations of components.

In certain alternative embodiments, network node 1660 may not includeseparate radio front end circuitry 1692, instead, processing circuitry1670 may comprise radio front end circuitry and may be connected toantenna 1662 without separate radio front end circuitry 1692. Similarly,in some embodiments, all or some of RF transceiver circuitry 1672 may beconsidered a part of interface 1690. In still other embodiments,interface 1690 may include one or more ports or terminals 1694, radiofront end circuitry 1692, and RF transceiver circuitry 1672, as part ofa radio unit (not shown), and interface 1690 may communicate withbaseband processing circuitry 1674, which is part of a digital unit (notshown).

Antenna 1662 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 1662 may becoupled to radio front end circuitry 1690 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 1662 may comprise one or moreomni-directional, sector or panel antennas operable to transmit/receiveradio signals between, for example, 2 GHz and 66 GHz. Anomni-directional antenna may be used to transmit/receive radio signalsin any direction, a sector antenna may be used to transmit/receive radiosignals from devices within a particular area, and a panel antenna maybe a line of sight antenna used to transmit/receive radio signals in arelatively straight line. In some instances, the use of more than oneantenna may be referred to as MIMO. In certain embodiments, antenna 1662may be separate from network node 1660 and may be connectable to networknode 1660 through an interface or port.

Antenna 1662, interface 1690, and/or processing circuitry 1670 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 1662, interface 1690, and/or processing circuitry 1670 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 1687 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node1660 with power for performing the functionality described herein. Powercircuitry 1687 may receive power from power source 1686. Power source1686 and/or power circuitry 1687 may be configured to provide power tothe various components of network node 1660 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 1686 may either be included in,or external to, power circuitry 1687 and/or network node 1660. Forexample, network node 1660 may be connectable to an external powersource (e.g., an electricity outlet) via an input circuitry or interfacesuch as an electrical cable, whereby the external power source suppliespower to power circuitry 1687. As a further example, power source 1686may comprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 1687. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 1660 may include additionalcomponents beyond those shown in FIG. 16 that may be responsible forproviding certain aspects of the network node's functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 1660 may include user interface equipment to allow input ofinformation into network node 1660 and to allow output of informationfrom network node 1660. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node1660.

As used herein, wireless device (WD) refers to a device capable,configured, arranged and/or operable to communicate wirelessly withnetwork nodes and/or other wireless devices. Unless otherwise noted, theterm WD may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a WD may be configured to transmitand/or receive information without direct human interaction. Forinstance, a WD may be designed to transmit information to a network on apredetermined schedule, when triggered by an internal or external event,or in response to requests from the network. Examples of a WD include,but are not limited to, a smart phone, a mobile phone, a cell phone, avoice over IP (VoIP) phone, a wireless local loop phone, a desktopcomputer, a personal digital assistant (PDA), a wireless cameras, agaming console or device, a music storage device, a playback appliance,a wearable terminal device, a wireless endpoint, a mobile station, atablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a smart device, a wireless customer-premise equipment(CPE). a vehicle-mounted wireless terminal device, etc. A WD may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may inthis case be referred to as a D2D communication device. As yet anotherspecific example, in an Internet of Things (IoT) scenario, a WD mayrepresent a machine or other device that performs monitoring and/ormeasurements, and transmits the results of such monitoring and/ormeasurements to another WD and/or a network node. The WD may in thiscase be a machine-to-machine (M2M) device, which may in a 3GPP contextbe referred to as an MTC device. As one particular example, the WD maybe a UE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g. refrigerators, televisions, etc.) personalwearables (e.g., watches, fitness trackers, etc.). In other scenarios, aWD may represent a vehicle or other equipment that is capable ofmonitoring and/or reporting on its operational status or other functionsassociated with its operation. A WD as described above may represent theendpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a WD as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

As illustrated, wireless device 1610 includes antenna 1611, interface1614, processing circuitry 1620, device readable medium 1630, userinterface equipment 1632, auxiliary equipment 1634, power source 1636and power circuitry 1637. WD 1610 may include multiple sets of one ormore of the illustrated components for different wireless technologiessupported by WD 1610, such as, for example, GSM, WCDMA, LTE, NR, WiFi,WiMAX, NB-IoT, or Bluetooth wireless technologies, just to mention afew. These wireless technologies may be integrated into the same ordifferent chips or set of chips as other components within WD 1610.

Antenna 1611 may include one or more antennas or antenna arrays,configured to send and/or receive wireless signals, and is connected tointerface 1614. In certain alternative embodiments, antenna 1611 may beseparate from WD 1610 and be connectable to WD 1610 through an interfaceor port. Antenna 1611, interface 1614, and/or processing circuitry 1620may be configured to perform any receiving or transmitting operationsdescribed herein as being performed by a WD. Any information, dataand/or signals may be received from a network node and/or another WD. Insome embodiments, radio front end circuitry and/or antenna 1611 may beconsidered an interface.

As illustrated, interface 1614 comprises radio front end circuitry 1612and antenna 1611. Radio front end circuitry 1612 comprise one or morefilters 1618 and amplifiers 1616. Radio front end circuitry 1614 isconnected to antenna 1611 and processing circuitry 1620, and isconfigured to condition signals communicated between antenna 1611 andprocessing circuitry 1620. Radio front end circuitry 1612 may be coupledto or a part of antenna 1611. In some embodiments, WD 1610 may notinclude separate radio front end circuitry 1612; rather, processingcircuitry 1620 may comprise radio front end circuitry and may beconnected to antenna 1611. Similarly, in some embodiments, some or allof RF transceiver circuitry 1622 may be considered a part of interface1614. Radio front end circuitry 1612 may receive digital data that is tobe sent out to other network nodes or WDs via a wireless connection.Radio front end circuitry 1612 may convert the digital data into a radiosignal having the appropriate channel and bandwidth parameters using acombination of filters 1618 and/or amplifiers 1616. The radio signal maythen be transmitted via antenna 1611. Similarly, when receiving data,antenna 1611 may collect radio signals which are then converted intodigital data by radio front end circuitry 1612. The digital data may bepassed to processing circuitry 1620. In other embodiments, the interfacemay comprise different components and/or different combinations ofcomponents.

Processing circuitry 1620 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other WD 1610components, such as device readable medium 1630, WD 1610 functionality.Such functionality may include providing any of the various wirelessfeatures or benefits discussed herein. For example, processing circuitry1620 may execute instructions stored in device readable medium 1630 orin memory within processing circuitry 1620 to provide the functionalitydisclosed herein.

As illustrated, processing circuitry 1620 includes one or more of RFtransceiver circuitry 1622, baseband processing circuitry 1624, andapplication processing circuitry 1626. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry1620 of WD 1610 may comprise a SOC. In some embodiments, RF transceivercircuitry 1622, baseband processing circuitry 1624, and applicationprocessing circuitry 1626 may be on separate chips or sets of chips. Inalternative embodiments, part or all of baseband processing circuitry1624 and application processing circuitry 1626 may be combined into onechip or set of chips, and RF transceiver circuitry 1622 may be on aseparate chip or set of chips. In still alternative embodiments, part orall of RF transceiver circuitry 1622 and baseband processing circuitry1624 may be on the same chip or set of chips, and application processingcircuitry 1626 may be on a separate chip or set of chips. In yet otheralternative embodiments, part or all of RF transceiver circuitry 1622,baseband processing circuitry 1624, and application processing circuitry1626 may be combined in the same chip or set of chips. In someembodiments, RF transceiver circuitry 1622 may be a part of interface1614. RF transceiver circuitry 1622 may condition RF signals forprocessing circuitry 1620.

In certain embodiments, some or all of the functionality describedherein as being performed by a WD may be provided by processingcircuitry 1620 executing instructions stored on device readable medium1630, which in certain embodiments may be a computer-readable storagemedium. In alternative embodiments, some or all of the functionality maybe provided by processing circuitry 1620 without executing instructionsstored on a separate or discrete device readable storage medium, such asin a hard-wired manner. In any of those particular embodiments, whetherexecuting instructions stored on a device readable storage medium ornot, processing circuitry 1620 can be configured to perform thedescribed functionality. The benefits provided by such functionality arenot limited to processing circuitry 1620 alone or to other components ofWD 1610, but are enjoyed by WD 1610 as a whole, and/or by end users andthe wireless network generally.

Processing circuitry 1620 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a WD. These operations, asperformed by processing circuitry 1620, may include processinginformation obtained by processing circuitry 1620 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedby WD 1610, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Device readable medium 1630 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 1620. Device readable medium 1630 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 1620. In someembodiments, processing circuitry 1620 and device readable medium 1630may be considered to be integrated.

User interface equipment 1632 may provide components that allow for ahuman user to interact with WD 1610. Such interaction may be of manyforms, such as visual, audial, tactile, etc. User interface equipment1632 may be operable to produce output to the user and to allow the userto provide input to WD 1610. The type of interaction may vary dependingon the type of user interface equipment 1632 installed in WD 1610. Forexample, if WD 1610 is a smart phone, the interaction may be via a touchscreen; if WD 1610 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 1632 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 1632 is configured to allow input of information into WD 1610,and is connected to processing circuitry 1620 to allow processingcircuitry 1620 to process the input information. User interfaceequipment 1632 may include, for example, a microphone, a proximity orother sensor, keys/buttons, a touch display, one or more cameras, a USBport, or other input circuitry. User interface equipment 1632 is alsoconfigured to allow output of information from WD 1610, and to allowprocessing circuitry 1620 to output information from WD 1610. Userinterface equipment 1632 may include, for example, a speaker, a display,vibrating circuitry, a USB port, a headphone interface, or other outputcircuitry. Using one or more input and output interfaces, devices, andcircuits, of user interface equipment 1632, WD 1610 may communicate withend users and/or the wireless network, and allow them to benefit fromthe functionality described herein.

Auxiliary equipment 1634 is operable to provide more specificfunctionality which may not be generally performed by WDs. This maycomprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 1634 may vary depending on the embodiment and/or scenario.

Power source 1636 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. WD 1610 may further comprise power circuitry1637 for delivering power from power source 1636 to the various parts ofWD 1610 which need power from power source 1636 to carry out anyfunctionality described or indicated herein. Power circuitry 1637 may incertain embodiments comprise power management circuitry. Power circuitry1637 may additionally or alternatively be operable to receive power froman external power source; in which case WD 1610 may be connectable tothe external power source (such as an electricity outlet) via inputcircuitry or an interface such as an electrical power cable. Powercircuitry 1637 may also in certain embodiments be operable to deliverpower from an external power source to power source 1636. This may be,for example, for the charging of power source 1636. Power circuitry 1637may perform any formatting, converting, or other modification to thepower from power source 1636 to make the power suitable for therespective components of WD 1610 to which power is supplied.

FIG. 17 illustrates one embodiment of a UE in accordance with variousaspects described herein. As used herein, a user equipment or UE may notnecessarily have a user in the sense of a human user who owns and/oroperates the relevant device. Instead, a UE may represent a device thatis intended for sale to, or operation by, a human user but which maynot, or which may not initially, be associated with a specific humanuser (e.g., a smart sprinkler controller). Alternatively, a UE mayrepresent a device that is not intended for sale to, or operation by, anend user but which may be associated with or operated for the benefit ofa user (e.g., a smart power meter). UE 17200 may be any UE identified bythe 3^(rd) Generation Partnership Project (3GPP), including a NB-IoT UE,a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.UE 1700, as illustrated in FIG. 17, is one example of a WD configuredfor communication in accordance with one or more communication standardspromulgated by the 3^(rd) Generation Partnership Project (3GPP), such as3GPP's GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, theterm WD and UE may be used interchangeable. Accordingly, although FIG.17 is a UE, the components discussed herein are equally applicable to aWD, and vice-versa.

In FIG. 17, UE 1700 includes processing circuitry 1701 that isoperatively coupled to input/output interface 1705, radio frequency (RF)interface 1709, network connection interface 1711, memory 1715 includingrandom access memory (RAM) 1717, read-only memory (ROM) 1719, andstorage medium 1721 or the like, communication subsystem 1731, powersource 1733, and/or any other component, or any combination thereof.Storage medium 1721 includes operating system 1723, application program1725, and data 1727. In other embodiments, storage medium 1721 mayinclude other similar types of information. Certain UEs may utilize allof the components shown in FIG. 17, or only a subset of the components.The level of integration between the components may vary from one UE toanother UE. Further, certain UEs may contain multiple instances of acomponent, such as multiple processors, memories, transceivers,transmitters, receivers, etc.

In FIG. 17, processing circuitry 1701 may be configured to processcomputer instructions and data. Processing circuitry 1701 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 1701 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer.

In the depicted embodiment, input/output interface 1705 may beconfigured to provide a communication interface to an input device,output device, or input and output device. UE 1700 may be configured touse an output device via input/output interface 1705. An output devicemay use the same type of interface port as an input device. For example,a USB port may be used to provide input to and output from UE 1700. Theoutput device may be a speaker, a sound card, a video card, a display, amonitor, a printer, an actuator, an emitter, a smartcard, another outputdevice, or any combination thereof. UE 1700 may be configured to use aninput device via input/output interface 1705 to allow a user to captureinformation into UE 1700. The input device may include a touch-sensitiveor presence-sensitive display, a camera (e.g., a digital camera, adigital video camera, a web camera, etc.), a microphone, a sensor, amouse, a trackball, a directional pad, a trackpad, a scroll wheel, asmartcard, and the like. The presence-sensitive display may include acapacitive or resistive touch sensor to sense input from a user. Asensor may be, for instance, an accelerometer, a gyroscope, a tiltsensor, a force sensor, a magnetometer, an optical sensor, a proximitysensor, another like sensor, or any combination thereof. For example,the input device may be an accelerometer, a magnetometer, a digitalcamera, a microphone, and an optical sensor.

In FIG. 17, RF interface 1709 may be configured to provide acommunication interface to RF components such as a transmitter, areceiver, and an antenna. Network connection interface 1711 may beconfigured to provide a communication interface to network 1743 a.Network 1743 a may encompass wired and/or wireless networks such as alocal-area network (LAN), a wide-area network (WAN), a computer network,a wireless network, a telecommunications network, another like networkor any combination thereof. For example, network 1743 a may comprise aWi-Fi network. Network connection interface 1711 may be configured toinclude a receiver and a transmitter interface used to communicate withone or more other devices over a communication network according to oneor more communication protocols, such as Ethernet, TCP/IP, SONET, ATM,or the like. Network connection interface 1711 may implement receiverand transmitter functionality appropriate to the communication networklinks (e.g., optical, electrical, and the like). The transmitter andreceiver functions may share circuit components, software or firmware,or alternatively may be implemented separately.

RAM 1717 may be configured to interface via bus 1702 to processingcircuitry 1701 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 1719 maybe configured to provide computer instructions or data to processingcircuitry 1701. For example, ROM 1719 may be configured to storeinvariant low-level system code or data for basic system functions suchas basic input and output (I/O), startup, or reception of keystrokesfrom a keyboard that are stored in a non-volatile memory. Storage medium1721 may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 1721 may be configured toinclude operating system 1723, application program 1725 such as a webbrowser application, a widget or gadget engine or another application,and data file 1727. Storage medium 1721 may store, for use by UE 1700,any of a variety of various operating systems or combinations ofoperating systems.

Storage medium 1721 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identity(SIM/RUIM) module, other memory, or any combination thereof. Storagemedium 1721 may allow UE 1700 to access computer-executableinstructions, application programs or the like, stored on transitory ornon-transitory memory media, to off-load data, or to upload data. Anarticle of manufacture, such as one utilizing a communication system maybe tangibly embodied in storage medium 1721, which may comprise a devicereadable medium.

In FIG. 17, processing circuitry 1701 may be configured to communicatewith network 1743 b using communication subsystem 1731. Network 1743 aand network 1743 b may be the same network or networks or differentnetwork or networks. Communication subsystem 1731 may be configured toinclude one or more transceivers used to communicate with network 1743b. For example, communication subsystem 1731 may be configured toinclude one or more transceivers used to communicate with one or moreremote transceivers of another device capable of wireless communicationsuch as another WD, UE, or base station of a radio access network (RAN)according to one or more communication protocols, such as IEEE 802.17,CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver mayinclude transmitter 1733 and/or receiver 1735 to implement transmitteror receiver functionality, respectively, appropriate to the RAN links(e.g., frequency allocations and the like). Further, transmitter 1733and receiver 1735 of each transceiver may share circuit components,software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 1731 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 1731 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 1743 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network1743 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 1713 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 1700.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 1700 or partitioned acrossmultiple components of UE 1700. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem1731 may be configured to include any of the components describedherein. Further, processing circuitry 1701 may be configured tocommunicate with any of such components over bus 1702. In anotherexample, any of such components may be represented by programinstructions stored in memory that when executed by processing circuitry1701 perform the corresponding functions described herein. In anotherexample, the functionality of any of such components may be partitionedbetween processing circuitry 1701 and communication subsystem 1731. Inanother example, the non-computationally intensive functions of any ofsuch components may be implemented in software or firmware and thecomputationally intensive functions may be implemented in hardware.

FIG. 18 is a schematic block diagram illustrating a virtualizationenvironment 1800 in which functions implemented by some embodiments maybe virtualized. In the present context, virtualizing means creatingvirtual versions of apparatuses or devices which may includevirtualizing hardware platforms, storage devices and networkingresources. As used herein, virtualization can be applied to a node(e.g., a virtualized base station or a virtualized radio access node) orto a device (e.g., a UE, a wireless device or any other type ofcommunication device) or components thereof and relates to animplementation in which at least a portion of the functionality isimplemented as one or more virtual components (e.g., via one or moreapplications, components, functions, virtual machines or containersexecuting on one or more physical processing nodes in one or morenetworks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 1800 hosted byone or more of hardware nodes 1830. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 1820 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 1820 are runin virtualization environment 1800 which provides hardware 1830comprising processing circuitry 1860 and memory 1890. Memory 1890contains instructions 1895 executable by processing circuitry 1860whereby application 1820 is operative to provide one or more of thefeatures, benefits, and/or functions disclosed herein.

Virtualization environment 1800, comprises general-purpose orspecial-purpose network hardware devices 1830 comprising a set of one ormore processors or processing circuitry 1860, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 1890-1 which may benon-persistent memory for temporarily storing instructions 1895 orsoftware executed by processing circuitry 1860. Each hardware device maycomprise one or more network interface controllers (NICs) 1870, alsoknown as network interface cards, which include physical networkinterface 1880. Each hardware device may also include non-transitory,persistent, machine-readable storage media 1890-2 having stored thereinsoftware 1895 and/or instructions executable by processing circuitry1860. Software 1895 may include any type of software including softwarefor instantiating one or more virtualization layers 1850 (also referredto as hypervisors), software to execute virtual machines 1840 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 1840, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 1850 or hypervisor. Differentembodiments of the instance of virtual appliance 1820 may be implementedon one or more of virtual machines 1840, and the implementations may bemade in different ways.

During operation, processing circuitry 1860 executes software 1895 toinstantiate the hypervisor or virtualization layer 1850, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 1850 may present a virtual operating platform thatappears like networking hardware to virtual machine 1840.

As shown in FIG. 18, hardware 1830 may be a standalone network node withgeneric or specific components. Hardware 1830 may comprise antenna 18225and may implement some functions via virtualization. Alternatively,hardware 1830 may be part of a larger cluster of hardware (e.g. such asin a data center or customer premise equipment (CPE)) where manyhardware nodes work together and are managed via management andorchestration (MANO) 18100, which, among others, oversees lifecyclemanagement of applications 1820.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 1840 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 1840, and that part of hardware 1830 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 1840, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 1840 on top of hardware networking infrastructure1830 and corresponds to application 1820 in FIG. 18.

In some embodiments, one or more radio units 18200 that each include oneor more transmitters 18220 and one or more receivers 18210 may becoupled to one or more antennas 18225. Radio units 18200 may communicatedirectly with hardware nodes 1830 via one or more appropriate networkinterfaces and may be used in combination with the virtual components toprovide a virtual node with radio capabilities, such as a radio accessnode or a base station.

In some embodiments, some signalling can be effected with the use ofcontrol system 18230 which may alternatively be used for communicationbetween the hardware nodes 1830 and radio units 18200.

FIG. 19 illustrates a telecommunication network connected via anintermediate network to a host computer in accordance with someembodiments. In particular, with reference to FIG. 19, in accordancewith an embodiment, a communication system includes telecommunicationnetwork 1910, such as a 3GPP-type cellular network, which comprisesaccess network 1911, such as a radio access network, and core network1914. Access network 1911 comprises a plurality of base stations 1912 a,1912 b, 1912 c, such as NBs, eNBs, gNBs or other types of wirelessaccess points, each defining a corresponding coverage area 1913 a, 1913b, 1913 c. Each base station 1912 a, 1912 b, 1912 c is connectable tocore network 1914 over a wired or wireless connection 1915. A first UE1991 located in coverage area 1913 c is configured to wirelessly connectto, or be paged by, the corresponding base station 1912 c. A second UE1992 in coverage area 1913 a is wirelessly connectable to thecorresponding base station 1912 a. While a plurality of UEs 1991, 1992are illustrated in this example, the disclosed embodiments are equallyapplicable to a situation where a sole UE is in the coverage area orwhere a sole UE is connecting to the corresponding base station 1912.

Telecommunication network 1910 is itself connected to host computer1930, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. Host computer 1930 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 1921 and 1922 between telecommunication network 1910 andhost computer 1930 may extend directly from core network 1914 to hostcomputer 1930 or may go via an optional intermediate network 1920.Intermediate network 1920 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 1920,if any, may be a backbone network or the Internet; in particular,intermediate network 1920 may comprise two or more sub-networks (notshown).

The communication system of FIG. 19 as a whole enables connectivitybetween the connected UEs 1991, 1992 and host computer 1930. Theconnectivity may be described as an over-the-top (OTT) connection 1950.Host computer 1930 and the connected UEs 1991, 1992 are configured tocommunicate data and/or signaling via OTT connection 1950, using accessnetwork 1911, core network 1914, any intermediate network 1920 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 1950 may be transparent in the sense that the participatingcommunication devices through which OTT connection 1950 passes areunaware of routing of uplink and downlink communications. For example,base station 1912 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 1930 to be forwarded (e.g., handed over) to a connected UE1991. Similarly, base station 1912 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 1991towards the host computer 1930.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 20. FIG. 20 illustrateshost computer communicating via a base station with a user equipmentover a partially wireless connection in accordance with some embodimentsIn communication system 2000, host computer 2010 comprises hardware 2015including communication interface 2016 configured to set up and maintaina wired or wireless connection with an interface of a differentcommunication device of communication system 2000. Host computer 2010further comprises processing circuitry 2018, which may have storageand/or processing capabilities. In particular, processing circuitry 2018may comprise one or more programmable processors, application-specificintegrated circuits, field programmable gate arrays or combinations ofthese (not shown) adapted to execute instructions. Host computer 2010further comprises software 2011, which is stored in or accessible byhost computer 2010 and executable by processing circuitry 2018. Software2011 includes host application 2012. Host application 2012 may beoperable to provide a service to a remote user, such as UE 2030connecting via OTT connection 2050 terminating at UE 2030 and hostcomputer 2010. In providing the service to the remote user, hostapplication 2012 may provide user data which is transmitted using OTTconnection 2050.

Communication system 2000 further includes base station 2020 provided ina telecommunication system and comprising hardware 2025 enabling it tocommunicate with host computer 2010 and with UE 2030. Hardware 2025 mayinclude communication interface 2026 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 2000, as well as radiointerface 2027 for setting up and maintaining at least wirelessconnection 2070 with UE 2030 located in a coverage area (not shown inFIG. 20) served by base station 2020. Communication interface 2026 maybe configured to facilitate connection 2060 to host computer 2010.Connection 2060 may be direct or it may pass through a core network (notshown in FIG. 20) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 2025 of base station 2020 further includesprocessing circuitry 2028, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 2020 further has software 2021 storedinternally or accessible via an external connection.

Communication system 2000 further includes UE 2030 already referred to.Its hardware 2035 may include radio interface 2037 configured to set upand maintain wireless connection 2070 with a base station serving acoverage area in which UE 2030 is currently located. Hardware 2035 of UE2030 further includes processing circuitry 2038, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 2030 further comprisessoftware 2031, which is stored in or accessible by UE 2030 andexecutable by processing circuitry 2038. Software 2031 includes clientapplication 2032. Client application 2032 may be operable to provide aservice to a human or non-human user via UE 2030, with the support ofhost computer 2010. In host computer 2010, an executing host application2012 may communicate with the executing client application 2032 via OTTconnection 2050 terminating at UE 2030 and host computer 2010. Inproviding the service to the user, client application 2032 may receiverequest data from host application 2012 and provide user data inresponse to the request data. OTT connection 2050 may transfer both therequest data and the user data. Client application 2032 may interactwith the user to generate the user data that it provides.

It is noted that host computer 2010, base station 2020 and UE 2030illustrated in FIG. 20 may be similar or identical to host computer1930, one of base stations 1912 a, 1912 b, 1912 c and one of U Es 1991,1992 of FIG. 19, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 20 and independently, thesurrounding network topology may be that of FIG. 19.

In FIG. 20, OTT connection 2050 has been drawn abstractly to illustratethe communication between host computer 2010 and UE 2030 via basestation 2020, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 2030 or from the service provider operating host computer2010, or both. While OTT connection 2050 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 2070 between UE 2030 and base station 2020 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 2030 using OTT connection2050, in which wireless connection 2070 forms the last segment. Moreprecisely, the teachings of these embodiments may improve the complexityand security of a radio network node and wireless device.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 2050 between hostcomputer 2010 and UE 2030, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 2050 may be implemented in software 2011and hardware 2015 of host computer 2010 or in software 2031 and hardware2035 of UE 2030, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 2050 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 2011, 2031 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 2050 may include messageformat, retransmission settings, preferred routing etc.; thereconfiguring need not affect base station 2020, and it may be unknownor imperceptible to base station 2020. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 2010′s measurements of throughput,propagation times, latency and the like. The measurements may beimplemented in that software 2011 and 2031 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 2050 while it monitors propagation times, errors etc.

FIG. 21 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 21will be included in this section. In step 2110, the host computerprovides user data. In substep 2111 (which may be optional) of step2110, the host computer provides the user data by executing a hostapplication. In step 2120, the host computer initiates a transmissioncarrying the user data to the UE. In step 2130 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 2140 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 22 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 22will be included in this section. In step 2210 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step2220, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 2230 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 23 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 23will be included in this section. In step 2310 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 2320, the UE provides user data. In substep2321 (which may be optional) of step 2320, the UE provides the user databy executing a client application. In substep 2311 (which may beoptional) of step 2310, the UE executes a client application whichprovides the user data in reaction to the received input data providedby the host computer. In providing the user data, the executed clientapplication may further consider user input received from the user.Regardless of the specific manner in which the user data was provided,the UE initiates, in substep 2330 (which may be optional), transmissionof the user data to the host computer. In step 2340 of the method, thehost computer receives the user data transmitted from the UE, inaccordance with the teachings of the embodiments described throughoutthis disclosure.

FIG. 24 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 19 and 20. Forsimplicity of the present disclosure, only drawing references to FIG. 24will be included in this section. In step 2410 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 2420 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step2430 (which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according one or more embodiments ofthe present disclosure.

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features andadvantages of the enclosed embodiments will be apparent from thedescription.

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, memories, logic solid state and/or discrete devices,computer programs or instructions for carrying out respective tasks,procedures, computations, outputs, and/or displaying functions, and soon, as such as those that are described herein.

Some of the embodiments contemplated herein are described more fullywith reference to the accompanying drawings. Other embodiments, however,are contained within the scope of the subject matter disclosed herein.The disclosed subject matter should not be construed as limited to onlythe embodiments set forth herein; rather, these embodiments are providedby way of example to convey the scope of the subject matter to thoseskilled in the art.

1.-40. (canceled)
 41. A method performed by a wireless device, themethod comprising: transmitting, to a radio network node, a radioresource control, RRC, connection request that requests theestablishment, re-establishment, or resumption of an RRC connection andthat indicates a type of core network to which the wireless deviceselects to connect, wherein the transmitting of the RRC connectionrequest is without integrity protection and/or confidentialityprotection, and receiving a response to the RRC connection request thatis integrity protected and/or confidentiality protected according to asecurity algorithm that depends on a type of core network indicated bythe RRC connection request .
 42. The method of claim 41, wherein the RRCconnection request indicates the type of core network to which thewireless device selects to connect based on a type of the RRC connectionrequest, wherein different possible types of RRC connection requestsindicate different possible types of core networks to which the wirelessdevice selects to connect.
 43. The method of claim 41, furthercomprising selecting a type of core network to which to connect andgenerating the RRC connection request to indicate the selected type ofcore network.
 44. The method of claim 41, comprising transmitting theRRC connection request on a first type of signaling bearer that uses afirst protocol stack, and further comprising receiving a response to theRRC connection request on a second type of signaling bearer that usesdifferent possible protocol stacks depending on a type of core networkindicated by the RRC connection request.
 45. The method of claim 44,wherein the different possible protocol stacks have different versionsof a packet data convergence protocol, PDCP.
 46. The method of claim 41,further comprising: receiving a response to the RRC connection requestbased on the type of core network to which the wireless device selectsto connect.
 47. The method of claim 46, wherein said receivingcomprises: determining, from different possible protocol stackssupported by the wireless device for receiving a response to the RRCconnection request and based on the type of core network to which thewireless device selects to connect, a protocol stack to use forreceiving the response to the RRC connection request; and receiving theresponse to the RRC connection request using the determined protocolstack.
 48. A method performed by a radio network node, the methodcomprising: receiving, from a wireless device, a radio resource control,RRC, connection request that requests the establishment,re-establishment, or resumption of an RRC connection and that indicatesa type of core network to which the wireless device selects to connect,wherein the received RRC connection request is without integrityprotection and/or confidentiality protection, selecting, based on a typeof core network indicated by the RRC connection request, a securityalgorithm to use to apply integrity protection and/or confidentialityprotection to a response to the RRC connection request, applyingintegrity protection and/or confidentiality protection to the responseusing the selected security algorithm, and transmitting the response asintegrity protected and/or confidentiality protected.
 49. The method ofclaim 48, wherein the RRC connection request indicates the type of corenetwork to which the wireless device selects to connect based on a typeof the RRC connection request, wherein different possible types of RRCconnection requests indicate different possible types of core networksto which the wireless device selects to connect.
 50. The method of claim48, comprising receiving the RRC connection request on a first type ofsignaling bearer that uses a first protocol stack, and furthercomprising: selecting, based on a type of core network indicated by theRRC connection request and from different possible protocol stackssupported by the radio network node, a protocol stack to use for asecond type of signaling bearer on which to transmit a response to theRRC connection request; and transmitting the response to the RRCconnection request on the second type of signaling bearer using theselected protocol stack.
 51. The method of claim 48, further comprising:transmitting a response to the RRC connection request based on the typeof core network to which the wireless device selects to connect.
 52. Themethod of claim 51, wherein said transmitting comprises: determining,from different possible protocol stacks supported by the radio networknode for transmitting the response to the RRC connection request andbased on the type of core network to which the wireless device selectsto connect, a protocol stack to use for transmitting the response to theRRC connection request; and transmitting the response to the RRCconnection request using the determined protocol stack.
 53. A methodperformed by a radio network node, the method comprising: receiving,from a wireless device, a radio resource control, RRC, connectionrequest that requests the re-establishment or resumption of an RRCconnection; responsive to the RRC connection request, attempting toretrieve a context for the wireless device for re-establishing orresuming the RRC connection; and determining, based on said attemptingto retrieve the context for the wireless device, a type of core networkto which the wireless device selects to connect.
 54. The method of claim53, further comprising, before receiving the RRC connection request,releasing or suspending the RRC connection and storing core network typeinformation in the context for the wireless device or in associationwith the context for the wireless device, wherein the core network typeinformation indicates the type of core network to which the wirelessdevice selected to connect for the RRC connection, wherein saiddetermining comprises determining said type based on the core networktype information stored in or in association with the retrieved context.55. The method of claim 53, further comprising, before receiving the RRCconnection request, releasing or suspending the RRC connection andstoring the context for the wireless device in one of multiple differentpossible storage locations respectively associated with differentpossible types of core networks selectable by the wireless device,wherein said attempting comprises attempting to retrieve the contextfrom one or more of the multiple different possible storage locationsand wherein said determining comprises determining said type based onfrom which possible storage location the context is successfullyretrieved.
 56. The method of claim 53, wherein said attempting comprisesattempting to retrieve the context for the wireless device over one ormore of multiple different types of interfaces to another radio networknode respectively associated with different types of core networks, andwherein said determining comprises determining said type based on overwhich type of interface the context is successfully retrieved.
 57. Themethod of claim 55, further comprising retrieving multiple candidatecontexts that are candidates for being the context for the wirelessdevice, and determining which of the candidate contexts comprises thecontext for the wireless device based on which of the candidate contextsincludes a security token that is verified by the radio network node.58. The method of claim 53, further comprising transmitting a responseto the RRC connection request based on the type of core networkdetermined.
 59. The method of claim 53, comprising receiving the RRCconnection request without integrity protection and/or confidentialityprotection, and further comprising: selecting, based on the type of corenetwork determined, a security algorithm to use to apply integrityprotection and/or confidentiality protection to a response to the RRCconnection request; applying integrity protection and/or confidentialityprotection to the response using the selected security algorithm; andtransmitting the response as integrity protected and/or confidentialityprotected.
 60. The method of claim 53, comprising receiving the RRCconnection request on a first type of signaling bearer that uses a firstprotocol stack, and further comprising: selecting, based on the type ofcore network determined and from different possible protocol stackssupported by the radio network node, a protocol stack to use for asecond type of signaling bearer on which to transmit a response to theRRC connection request; and transmitting the response to the RRCconnection request on the second type of signaling bearer using theselected protocol stack.
 61. A wireless device comprising: communicationcircuitry; and processing circuitry configured to transmit, to a radionetwork node, a radio resource control, RRC, connection request thatrequests the establishment, re-establishment, or resumption of an RRCconnection and that indicates a type of core network to which thewireless device selects to connect, wherein the transmitted RRCconnection request is without integrity protection and/orconfidentiality protection, and receive a response to the RRC connectionrequest that is integrity protected and/or confidentiality protectedaccording to a security algorithm that depends on a type of core networkindicated by the RRC connection request.
 62. The wireless device ofclaim 61, wherein the RRC connection request indicates the type of corenetwork to which the wireless device selects to connect based on a typeof the RRC connection request, wherein different possible types of RRCconnection requests indicate different possible types of core networksto which the wireless device selects to connect.
 63. A radio networknode comprising: communication circuitry; and processing circuitryconfigured to receive, from a wireless device, a radio resource control,RRC, connection request that requests the establishment,re-establishment, or resumption of an RRC connection and that indicatesa type of core network to which the wireless device selects to connect,wherein the received RRC connection request is without integrityprotection and/or confidentiality protection, select, based on a type ofcore network indicated by the RRC connection request, a securityalgorithm to use to apply integrity protection and/or confidentialityprotection to a response to the RRC connection request, apply integrityprotection and/or confidentiality protection to the response using theselected security algorithm, and transmit the response as integrityprotected and/or confidentiality protected.
 64. The radio network nodeof claim 63, wherein the RRC connection request indicates the type ofcore network to which the wireless device selects to connect based on atype of the RRC connection request, wherein different possible types ofRRC connection requests indicate different possible types of corenetworks to which the wireless device selects to connect.
 65. A radionetwork node comprising: communication circuitry; and processingcircuitry configured to: receive, from a wireless device, a radioresource control, RRC, connection request that requests there-establishment or resumption of an RRC connection; responsive to theRRC connection request, attempt to retrieve a context for the wirelessdevice for re-establishing or resuming the RRC connection; anddetermine, based on said attempting to retrieve the context for thewireless device, a type of core network to which the wireless deviceselects to connect.
 66. The radio network node of claim 65, theprocessing circuitry further configured to, before receiving the RRCconnection request, release or suspend the RRC connection and store corenetwork type information in the context for the wireless device or inassociation with the context for the wireless device, wherein the corenetwork type information indicates the type of core network to which thewireless device selected to connect for the RRC connection, wherein saidtype of core network is determined based on the core network typeinformation stored in or in association with the retrieved context.